What (if any) difference is there in the duration of mitosis in plants versus animals?

The cell division process overall varies in time between plants and animals, but the mitosis stage takes roughly the same amount of time: 2 hours. The whole process of cell division takes around 20 hours for animals and up to about 24 hours for plants, namely because of the different structures that need to be duplicated (chloroplasts and a rigid cell wall, for example).
Mitosis is the stage in the process where the duplicated cell finalizes its division and performs cytokinesis, pinching the cell barrier and creating two separate cells. The overall process before this takes some extended time, but it resolves rather quickly with the final mitosis event—separating into the two unique cells in a matter of hours.