Kevin, Try Acetone, mask off the door with some cardboard so the acetone dosen't run down the door. You will need to get a small paint brush to try and work it in the lock, once the cover plate opens you can dip the key in the acetone and work it in the lock. You will also need to flush out the lock. Once you get it to work, spray in lots of WD-40 (this isnt something you normaly want in a lockset)
The only other thing you could do is open the door with a slim jim and take the car to a locksmith.