where to store your keys

I learned today not to store my pinball keys in the coin return box of a coindoor..

Usually I just leave the keys on the game in the lock. This works for all my games.
But on my Cactus Canyon, there's a lock installed with a round key. The problem is that the key pops out when the lock is in the locked position. So I had to search for another place to store that key.
My first idea was to put it in the coin return box of a coindoor. Behind the metal plate it's hidden out of view, and you can easily reach it when you need it.
I'd seen some other collectors also store their keys in that place.

When I wanted to lower the volume on Cactus Canyon earlier this evening, I discovered my idea to store the key in the coinreturn wasn't that good..
I have a big box of tokens, and my daughter likes to drop coins in the games.. even when they're switched off. So I had a coinreturn that was filled with jammed coins.
Had to remove them one by one until the metal plate could be moved back enough to remove the key and the rest of the tokens..