Langmead equalised two minutes from time to keep the Cobblers in fourth place after Jack Redshaw had given the home side the lead.
Boothroyd's side are two points behind third-placed Port Vale with eight games remaining, and the Cobblers boss was delighted with his side's performance.
"It was a great point and I think one we fully deserved," he said.
"I did think it wasn't going to be our day after we hit the post three times in the first half but we kept battling to the end and I was delighted for Kelvin because I thought he was exceptional.
"In truth there were a lot of good performances and I thought it was one of our best displays away from home for some time.
"If we continue to play like that we will win far more games than we lose.
"It was a great game and on another day we could have won 4-3 but I will settle for a point."
- Sports & Recreation
- Jack Redshaw