1984 Chevrolet Camaro Door Problems

So this morning I went to unlock my drivers side door and it won't unlock. I can get the key to go in and wiggle it either way just a little bit, but not enough to unlock it. Passenger side door works just fine. Crawled in that side and tried to unlock drivers side door from the inside with no luck, the lock just moves a little bit. Again not enough to unlock the car. Thought maybe my lock is froze up seeing as it's -3° this morning. So I tried heating up the key a few times with a lighter but that didn't seem to work. I don't have a hair dryer or any deicer. Could it just be froze up or is something broke here. Door and lock worked just fine three days ago. Any ideas here?