Results: $0.52 pot ($0.02 rake)
Final Board: T 3 Q A J
BTN mucked and won $0.50 ($0.33 net)
Hero mucked Q T and lost (-$0.17 net)
MP1 mucked and lost (-$0.17 net)
He limped on the BTN with one limper in front so you can exclude most of those hands from his range. But there are plenty of Kx hands in his range that he might limp: K2-KTs, KT-KQ. There are also sets that beat you (33/TT) and better 2P (A3/AT/QJ). There just aren't many hands you beat there. Maybe he thinks he can push you off on such a scary board after you both checked but 2NL players aren't generally that tricky.