An hour is fast for any Disney restaurant, especially character dining.
For our part, we were seated at about 4:50pm and had seen all characters, including going up to meet the queen, by 5:38pm. We had our mains at the time but no dessert yet. From there, things stretched out quite a bit, but that was because my kids were eating at a snail's pace. The sever came over a couple times to check on us before I finally had her clear the plates and bring dessert. Had kids been more motivated to eat quickly, I would say we could have been done in 75-90 minutes, but not much faster than that.