Lock is not very sturdy
I can't be sure about your version, but ours is cheapest variety of rotating cabinet lock there is, with stamped key and minimal mechanism...
I'd try small flat screwdriver inserted into slot and wiggled aggressively while trying to rotate lock cylinder 90 degrees clockwise or counterclockwise (should move one way or the other..). After opening, you can replace with cabinet lock from almost any hardware store, if you want more secure.
I think Airstream owners also got frustrated with all the other keys required. For ours, each storage compartment (2) and each battery compartment (2) plus door (1) and water door (1) and hitch area storage padlock (1) plus hitch bar lock pin (1) and hitch lock (1) all require separate keys... Means trailer has its own keychains, and much potential for loss.. Add truck key, with locking gas cap, The Club, house key and I may need bigger pockets...
In Theory, there's no difference between Theory and Practice, but in Practice, there is usually a difference...