If the steering is locked, turn and hold the steering wheel all they way counterclockwise while trying to turn the key. Sometimes the steering lock will jam and prevent the key to be turned.
It would not be the fuse. It is most likely a worn ignition switch that is binding. You can try a little WD-40 spray into the switch to see if that helps. If not, you'll need to replace the switch itself.
Let me know if that works. If not, we'll take it from there.