storage door lock

My truck cap lock was the same way. Watched a youtube video that said to squirt some penetrating oil inside where the key goes. Let it soak for awhile, then get a set of pliers and grip the key as close to the lock as possible and wiggle it, then slowly try to turn it. Be careful as to not put too much pressure on it as that will bend or break off the key-then you've got a bigger problem. Tried it and after a few more squirts of oil and with the pliers it finally worked. Again, be careful not to turn the pliers too hard as to break or bend the key. gary