I had a similar issue.
I squirted a lot of graphite inside the ignition, coated the key with it.
I wiggled the steering wheel to help unlock ignition, then I kept slowly wiggling the key in the ignition, turning it back and forth, the more I did this the easier it got to unlock and turn key, you may wanna try giving it a shot, also make sure your key is not overly worn down.
good-luck.