about how a broken lock can freak you

about 900 euro are in one drawer. the drawer is locked and i have the key. BUT...oh it wouldn't be so nice without the but...but the key won't work. means, the key does but the lock won't. people are filtering in and i am supposed to give them change - how?
ok this wasn't so much of a problem, I just borrowed the money and promised to give it back once the lock is open again...no problem if this is not today or tomorrow...that has time.
BUT - oh there it is again - but there are car keys and drivers licences in the drawer too, things that I'm supposed to give back to the clients...haha.
thing is, it took me 30 minutes to give up. the lock wouldn't open with any sort of breaking-in-device, like a paper-clip or something.
now I just broke it open...it still looks intact. there is nothing wrong. it's just that all of a sudden the key won't go in anymore...