Ignition locked in cold? WHY!?!?

So, I go outside today and it’s -8 w/o windchill, but -22 with windchill. I have a 2002 Chevrolet Prism (which, to those uninformed on this fact, it’s a Toyota Corolla at heart). I go outside this morning and the same thing happened yesterday, but I got it started. But the steering wheel is free to turn as if it has no electric assist, as well as the ignition is locked. I would have thought it was the whole ordeal where you whiggle the wheel side to side and it unlocks, but the steering wheel is normally the one locked. This time, the key doesn’t turn. Why?

Although the grease or lubricant in there would not be thought to contain freezable water, The slight moisture content is finaly freezing at these temps. Or maybe there’s new moisture this time that didn’t exist in years past…Once upon a time, long ago, I dropped my keys in the snow, picked them up and ran the car that day, then over night the moisture I brought in that morning froze the ignition lock. Brought out the hair dryer and gave it a once over and problem solved.