I would say about an hour for MK and 40 minutes for the others.
There are a lot of variables, for example, it may take 15 minutes for drive, but then 10 minutes to wait for the parking tram, then 10 minutes through security.
MK is the longest because you park at the TTC and then have to take the boat or monorail. It always takes longer than you think.
If you are thinking of rope-dropping, easywdw.com has good info on when you should arrive at the parks.