Help open 36 spare tire lock

[Ford coupe]

I am sure i have the correct key to open my 36 spare tire lock but the lock just will not turn..I have put pen oil in but to no avail..Does that lock push down through a hole in the spare carrier and the two little fingers extend out and not let it come back until you turn the key and retract them??If so the fingers could be stuck to the hole and hence i can not turn the key..I just hate to drill it out as the locks are expensive and hard to come by..The key i have does not resemble the pic of a Hurd key but i am sure it came with the lock..Lock worked great when i installed it 3 yrs ago..Hope you guys can help Harry