In short

ID Card Police Station is a ID card for the building “Police Station” in Palm Side. It opens: locked room. Behind the door: Weapon Parts, LM 249 Mk2, Gas Grenade. The key fits only this place.

KeyBuildingDistrictOpens
ID Card Police StationPolice StationPalm SideLocked room

Where it is

The building is on the interactive map. All keys, doors and safes of the city: Locked doors, Safes and containers, the key guide.

The game data does not list where this key drops or is sold, so we do not guess.