Khan (27-3, 19 KOs) dominated every round and after telling Molina he was close to stopping the bout after the ninth, referee Jack Reiss waved off the fight at the end of the 10th following another one-sided round.
Before the bout, the Bolton fighter suggested he may adopt a more conservative style under new trainer Virgil Hunter after an overly aggressive approach led to a stunning knockout at the hands of American Danny Garcia in July.
However, it was business as usual at the Memorial Sports Arena for the Olympic silver medallist and former world champion from the opening bell, as Khan peppered Molina (17-1-1, 7 KOs) with his trademark blistering combinations.
Occasionally, Khan lingered too long after landing a flurry of punches and Molina was able to land a hard counter punch but the Briton shook off everything his opponent threw at him and went straight back to work.
By the fifth round, Khan, sensing he had the fight under control, relaxed and worked more efficiently and effectively behind the jab, which he used to back his opponent towards the ropes before following up with solid combinations.
"I thought I stuck to my game plan, which meant sticking to my jab," Khan told reporters. "Carlos took some really good shots and was still coming forward, and that's when I thought to myself I'd better stick to this game plan."
When the end came, Molina had asked the referee to allow the fight to continue and sounded stunned in defeat.
"I don't know what happened," the Californian said. "I wanted to pull the trigger but for some reason I couldn't get my hands to go. He was fast in his jab and I was hesitant in trying to get in."
After picking up a much-needed win, an ebullient Khan turned his attention towards setting up a rematch against the last man to beat him, who was sitting ringside.
"In that fight, he caught me with a good shot but I'll fight Danny Garcia again, anytime anywhere," he said.