If you don’t want to eat or see the shops before departing, grab your luggage after it has been scanned and instead of making the left towards the up escalator, go through the doors that are straight ahead (there may be a sign that says “AA personnel entrance” but no one cares or enforces it) instead of making the left towards the up escalator. That will save you the time of taking the escalator up, walking by the shops or restaurants and taking the escalator back down. It saves you a little time. I’m doing this from memory so I hope it is accurate. It’s been a month since I flew out of LGA’s new AA terminal.