Say my players are in a dungeon of many keys and many doors, where if a wrong key is used in the wrong door, they will be electrocuted, ambushed, etc. This makes the players wary to just try every key in every door. The players have found a key that I describe as "a simple key, made of copper stained green with age." Our session ends, and next week the players find a locked door. A perception check has them see the lock as "relatively simple, made of aged copper, turning green." Due to my players lack of note taking and poor memory over a week, they do not associate the key with the lock. In this scenario the players may have forgotten, but the characters likely wouldn’t have, but I do not want to just hand the players the answer.
After a few minutes of them unsuccessfully trying to get through the door that was never intended to be difficult puzzle, I want them to roll to recognize the similarities between the lock and the key they previously found.
An investigation check doesn’t seem appropriate, as they are not investigating anything for this, just thinking about it. A perception check doesn’t seem fitting either, as they have already seen the lock and key, they just need to recognize the similarities between them.
How should I have my players roll to deduce an answer to a simple question?