Shazam

In the movie Shazam Billy Batson's (Shazam) most cherished possession is a compass keychain. Because the last time he saw his mother she won it for him at a carnival.

El Camino: A Breaking Bad Movie

This movie picks up right where Breaking Bad left off and follows the rest of Jesse Pinkman's (Aaron Paul) escape.  At the end of Breaking Bad Jesse drives off in Todd's El Camino, his keychain can be seen, a bottle opener, this the same keychain that can be seen in the final episode of breaking bad.  Jesse switches cars with his friends. Badger and Skinny Pete.  Skinny Pete's keychain is a die (single for dice) and a generic fob.  Badger's keychain is a posable hand.

Ash vs. Evil Dead

In the final scene of the series, the keys to Ash's Oldsmobile Delta are thrown to him.  His keychain is a bullet (a mainstay for badasses) and a skeleton arm which is just a perfect fit.  This keychain is throughout the show but not easily visible.

Always Be My Maybe

The Netflix movie Always Be My Maybe is a romantic comedy about childhood friends.  Marcus (Randall Park) is reminiscing about his past friendship with Sasha (Ali Wong) after he sees her for the first time in years.  He looks at a souvenir keychain they got at a fair with a picture of them inside it.

The Dark Knight

Harvey Dent kidnaps one of the Joker's stooges to interrogate him while he was being treated in an ambulance.  The ambulance has the keys in the ignition with keychain attached.  The keychain is a green fob with a logo or writing on it, but it is impossible to tell what that is.

Mission: Impossible - Fallout

From Mission: Impossible - Fallout

Ethan Hunt, Tom Cruise, is trying to keep a terrorist from escaping custody.  His getaway car has what appears to be just a plain blank keychain.  Disappointing.

Good Omens

Crawley's (Crowley's) 1926 black Bentley is his prized possession.  So, of course his keychain has a Bentley logo on it.  (The logo is slightly different than the real logo probably due to legal reasons.)  This screen cap is from episode 1 but the keychain can be seen several times throughout the show.

Once Upon a Time in Hollywood

Brad Pitt plays a stuntman (Cliff Booth) in this Quentin Tarantino historical fantasy film set in 1969 Hollywood.  His keychain is a miniature six shooter.  Several of Tarantino's other films have keychains prominently featured.  They can act as a small and simple prop to flesh out a character.

Toy Story of Terror (Short)

From the Disney Pixar television special Toy Story Of Terror. A red motel keychain that's very similar to this image from The Shining. In the audio commentary from the Toy Story Of Terror DVD release the filmmakers even mention the 'Kubrikian influence' on the scene.

From Treesa.  Thanks!

The Rocketeer

Cliff Secord's (Billy Campbell) keychain can been seen when his pockets are emptied in Howard Hugh's office.  His keychains are a blank metal circle, possibly a bullet, and a disc used for calculating for flying, which makes sense because he is a pilot.

The Division 2 (Video Game)

In the game The Division 2 keychains are collectible items.  They serve no purpose in the game other than being a collectible.  You can display your keychains on your backpack which is visible during gameplay.  There are many that you can find.  I only included two in the photos above.

Antiques Roadshow (UK)

I have only posted from scripted media before BUT I can do whatever I want so here's this... From the most recent season of the UK Antiques Roadshow, a couple had a keychain that went to the royal train in 1912. The king of the United Kingdom in 1912 was George V. The expert appraised the value at 200 to 400 pounds.

(from season 37 episode 5)

The Driver by Ollie Wride (feat. The Night Hour) Music Video

The singer's keys can be seen throughout the music video.  His keychain is a steering wheel.
Watch the video here:

The Flash

From season 5 episode 6  Frank (The Elongated Man) and Cecille are investigating to find out who is Cicada.  They confront a corrupt FEMA official to get information from him.  Frank holds up his Lamborghini keychain as evidence he has been stealing money from the government.

From season 5 epsisode 10   A new villain (Silver Ghost) breaks Weather Witch out of prison.  She has a meta tech keychain.  A piece of the dark matter infused satellite apparently attached to a car keychain granting the holder the ability to control some technology (mostly cars.)

My Hero Academia

The class move into their new dorms and they look at each others rooms to see which one is best.  Tokoyami has a goth style room with a keychain to match.

The Saint

The Saint, with Roger Moore. S06_E07 "The Double Take"
The Saint is kept in a house against his will. He says he has to go home to get some clothes. The bad guy says "No way, the butler will go for you" (meaning "Give him your car keys")

Malcolm in the Middle

Malcom in the Middle S01E08 14'10". The big brother just met that girl at the school party. But they pretend they'd been living together for years and years. They have a fight and they give back things one to the other. For instance, she says "i give you back that awful ring you offered me", he answers "i give you back your silly keyring" etc

Kingsman: the Golden Circle

Behind a wall in his house, Eggsy (Taron Egerton) has his secret agent tools and weapons.  Among them are keychains with the Kingsman logo on them.

Silicon Valley

From season 5 episode 8.  The guys need to get somewhere fast so they take the Tesla that Dinesh, Kumail Nanjiani, is paying for but doesn't actually own.  The Tesla keychain is most likely an electronic key for the car.

The Path

From season 3 episode 6.  Sarah Lane's (Michelle Monaghan) keychain is appropriately the symbol for her religion, the eye with rays around it.  The keychain is a wooden eye inside a metal frame.

Cobra Kai

Johnny Lawrence (William Zabka) is passed out on his floor after an apparent binge.  His firebird keychain matches his car, most likely an attempt to continue to live as he did in the 80's.

Counterpart

From season 1 episode 9.  The counterparts are preparing for their infiltration and assault.  One of their keychains can be seen, they are a bottle opener and some kind of clip.

28 Weeks Later

The kids escape the quarantine zone and find a scooter so they can return to their old home.  The key to the scooter is on a corpse and has a yellow plastic fob attached.

Get Out

When things really turn sideways Rose Armitage (Allison Williams) shows her keys and enamel bear face keychain to her boyfriend, Chris Washington (Daniel Kaluuya), signaling her true intentions. 

Captain America Civil War

Peter Parker AKA SpiderMan (Tom Holland) comes home to find Tony Stark there.  His house keys have a keychain on them.  It appears to be a dog tag, or just a generic gray fob.

Logan

Logan and Laura steal a fisherman's truck to continue their journey.  The fisherman's keychain is of course a fish.
Laura has a horse keychain attached to her backpack.

Monk

From Season 1 Episode 1.  Adrian Monk's (Tony Shalhoub) keychain is a silver "T", it belonged to his late wife Trudy.  Adrian is at a funeral for a case, he is sitting in a balcony. He misplaces his keys but finds them in his pocket.  He is so happy he is swinging them on his finger but they slip and fall into the open casket.  He tries to fish them out unnoticed with dental floss and a paperclip but fails in hilarious fashion.

From season 1 episode 6.  Adrian is investigating the death of a billionaire who tried to mug a man.  The victim of the mugging has a keychain with his college fraternity on it Phi Beta Tao.  This becomes an important clue later on.

Kong: Skull Island

One of the soldiers in the party keeps his rabbit's foot keychain on his helmet.

Rick and Morty

From season 1 episode 7, season 3 episode 7, and season 3 episode 2. 

Rick and Summer escape a planet controlled by females so naturally their vehicle is pink with a pink keychain. 

A Rick gives another Rick a gift of a new car, the keychain is a standard car fob. 

Summer is staying in an apocalyptic wasteland which has gotten somewhat civilized thanks to Rick, her Mad Max styled vehicle has an odd keychain, it might be a little skull.

Vice Principals

Russell shows Gamby the changes he has made to the school since becoming principal.  That includes changing the school mascot to the tigers.  Several shots of tigers merchandise were shown around the schools including keychains.  From season 2 episode 1

Preacher

From season 2 episode 6.  Preacher and the gang are in New Orleans and they need a soul.  All the normal soul dealers are getting pushed by a Japanese corporation.  The company uses an armored truck and to open it the guards must use both of their keys.  Their keychains have the company logo on them.

There's Something About Mary

Mary (Cameron Diaz) gives Ted (Ben Stiller) back his keys.  His keychain is a white rabbit's foot.

American Gods

While Shadow (Ricky Whittle) and Mr. Wednesday (Ian McShane) travel across the country on their mission they stay at various small motels.  Their keychains can be seen, a classic red diamond shape (from season 1 episode 1) and blue tag (from season 1 episode 3.)

In the season one finale Mr. Wednesday and Shadow travel to recruit Ostara/Easter (Kristin Chenoweth).  One of the Spring Goddess's well known symbols is the  Rabbit; Coincidentally(?) Mr. Wednesday is sporting a rabbit's foot keychain.

The Wolverine

Logan, the Wolverine, (Hugh Jackman) and Mariko (Tao Okamoto) are trying to hide from assassins so they pick an unlikely place, a "love hotel."  The hotel has differently themed rooms: a nurse's office, a mission to mars and a dungeon.  Each room key also has a keychain that matches the theme.  A red cross medallion, a rocket ship, and a pair of handcuffs.

Independence Day: Resurgence

David Levinson's (Jeff Goldblum) dad Julius (Judd Hirsch) stumbles across an abandoned group of kids and their bus.  He feels obliged to help them so he attempts to drive them to safety.  The bus' keys have a USA keychain.  Quite appropriate for this patriotic "franchise."

Superbad

At the beginning of the film Seth (Jonah Hill) picks up his best friend Evan (Michael Cera) and they head for school.  Seth's keychain can be seen which is a posable hand and it is set in an OK gesture.

Constantine

Constantine (Keanu Reeves) is performing an exorcism and he starts by attacking the demon with magical charms on his keychain.  They hurt the demon but it is far more powerful than he expected, foreshadowing a looming threat.  It is hard to make out details in the film but these pictures of the actual prop are quite clear.