You could go to the "Tune-In Lounge" which is also the waiting area for PTC. People can sit at the bar to order and eat meals, so there should be no problem there. However, it may not travel well in a box.
When we were there in December there was a couple in front of us that didn't have an ADR. They asked the CM if they could get carryout and the CM said they couldn't do carry out because they would never be able to keep up with all the folks inside too. so no table service at the Prime Time.
I agree with a previous poster - try the Tune In Lounge. I don't really like the antics inside the restaurant, but I love their PB&J Shakes - so I just have one at the lounge. Plenty of people are in there doing the same.
We didn't have time for a meal at 50's and we were needing a snack so we went into the Lounge and ordered the PB&J to go, that was a great pick me up for the afternoon.