Let's say you can get off the ship at 7 am (there have been at least 3 cruises that I've been on where you couldn't even start to disembark until 8:30 because of delays clearing customs). If you were the first off and moved quickly, you could probably grab your luggage, be through customs and in your mode of transportation in 15 minutes. With a 45 minute ride to the airport, you'd arrive at 8 am. You would then have 30-40 minutes (depending on when your airline requires you to be at the gate) to check any luggage, get through security and get to your gate. And that's if everything runs smoothly to that point. MCO is an airport that they recommend you arrive at least 2 hours in advance because there have been times it has taken over an hour just to get through security.
Could it physically be done? Maybe and only then if you get really lucky with the lines at security (and check-in if checking luggage). Personally, I wouldn't want the stress after a relaxing vacation.