I'm not sure if the Mara is open ALL the time, but it is open pretty late. We didn't have any food, but it seemed very popular. The wait at the cashier could be long though. (We went once for Mickey bars!!!!) I was impressed that you could also get fruit and quick food from the fridges on the side.
Mara is the typical food court and it isn't that bad. They do seem to be open late though. We have enjoyed getting quick meals there and have never had a problem with them.