Same thing happened to me in my Evotion Bijou. Tried vegetable oil, WD40, compressed air, citric acid, dental pick. Tried to force the lock and the first key broke. I was able to get the broken key out. Tried again, second key broke, key not able to be removed. The lock is frozen. There's a basic issue with a lock in a position where it can get corroded from urine.
I'll keep the site posted on how I manage to get it off. Hoping that I don't destroy the cage, but that is a real possibility. First line of attack will be a drill to the lock. If that fails, Dremel cutting tool to cut off the nylon near the lock.
Sent an email to Evotion asking for their advice, no reply received.
For the gearheads in the audience
I finally did receive a reply generally in line with what I planned: drill out the lock starting with the smallest drill. Haven't done it yet, will let you know how it goes.