Almost Human Season 1 Episode 3

In this cop drama set in 2047 locks with physical keys are a relic of the past.  But the woman in the beginning of this episode likes to keep the old technology and not opt for "bio locks".  She forgets her keys in her office door again and a security guard with a package for her gives her the keys back.  She has what appears to be a green alien keychain. 

The World's End

In this Sci Fi comedy the main character Gary King, played by Simon Pegg, gives up his keys after a few too many drinks and when things were looking bleak.  He has a black skull keychain and another which appears to be for a car brand.  I can't tell but it is a blue medallion on a leather fob. 

Dexter

There are several keychains featured in this showtime drama about the serial killer with a code Dexter Morgan, played by Michael C. Hall.

1.  Season 1 episode 5.  Dexter is investigating a possible target who is a human trafficker and murderer.  Dexter notices his red floatie keychain, concludes he must have a boat, and comments on it. 
2.  Season 1 episode 8.  Dexter received a note from another serial killer he admires, the ice truck killer, in the form of a doll.  Dexter took the doll's head and turned it into a keychain.
3.  Season 1 episode 10 The police department receives a message from the ice truck killer in the form of a jar of blood, blood he got from his victims.  In the jar is a hotel room keychain.  The police go to the hotel to investigate. 

R.I.P.D.

Nick (Ryan Reynolds) just died and finds himself in front of Proctor (Mary-Louise Parker) who inducts him in the Rest in Peace Department, R.I.P.D..  She gives Nick his equipment.  She also has a keychain which appears to have R.I.P.D. written on it.  It might be a locker key or the key to her desk but it is not shown again in the movie.  The keychain is a brass colored circle.