Driver's Door Lock frozen

[AaronA]

I have a 2001 V70 with 104,000 miles, and when I went to unlock the driver's door this morning with the key, it wouldn't turn at all. The remote worked fine and the door locks and unlocks normally with it. I try to use the key once every week or two to keep it clean and functional, so I know it worked about four days ago. I tried to lube it, but it's still stuck. Any ideas? It was 15 degrees this morning, so I thought it literally froze but there's not difference once the temperature is rising above freezing.

Do I need to get a new lock cylinder? Or is this one fixable? If I need a new one, does anyone know if I can get one that's keyed to the car so I don't have to have two different keys for the car? Is that a dealer part or is there a place on-line to buy it?

Thanks,
Aaron