I'm assuming your cruise ends in MIA, and that you have a 1:10 flight out. The purser's desk is going to ask to see your ticket before they grant you an "early debarkation" tag. That's usually reserved for noonish-earlier flights. General should be no problem (you'll probably leave no later than 10:30).
If you're talking about the "express debarkation"...please remember you have to be able to carry all luggage with you out of the ship/the terminal.