I have owned one of these trucks for 37 years and have looked at, parted out, robbed from MANY of them. They only had a key cyl on the passenger side. I even have a pair of NOS latches, key cyl on passenger side only, I have a number of doors, key on passenger side only.
If you have seen one with a key cyl on the drivers door, it was added. And by the way, I plan on adding one to mine.