Bought a 2007 Ranger and had a flat a few months later. Could not remove the spare cause it has a lock. Only key I was given was for the ignition.

 

I had the same problem when I got my 99 Ranger in '04. I took it to the dealer and they pryed out the existing lock and sold me a new lock/key set for like $20. You could probably pry the lock out yourself, but you have to go to a dealership if you want a new lock.