The cash register is probably a good place where to hide some spare key.
It is an old electronic cash register. As you might expect, the drawer is closed. In this particular model it can be opened in two ways: either by means of a physical key, or by entering a numeric password on the keyboard.
Oh, and of course you can try to pick the lock, but you would need some tool.
Oh no. I'm hungover and the obvious didn't work.
I'll need to search the kitchen for a key, a hair pin or a record of the number. But a staff room or office would be even better if I can find one.
(Great idea Kyle. Kudos)