menu says it opens wooden chests, but i can't find any in the game.
This is what it says in every of your games which feature rusty keys, I think this is the default description of this item and you never bothered to change it in any of your games even though you never actually use them to open wooden chests, you always use them to unlock doors. :-3
So I thought there is a locked door somewhere which unlocks with the rusty key but I didn't find any. Can you check the doors in the game?
i checked those first.
And you didn't find any which requires a rusty key to unlock? Then did you put this key in the game by mistake?