This can also be used as a troll term
This phrase, term, whatever, came from the great Tom Hiddleston, who is either: truly Loki, Loki’s spirit animal, or the other way around.
Person 1 (with tray of food): "What, probably around ten bucks right?"
Cashier: "Actually it's already been paid for"
Person 1: "What?"
Person 2: "HEHEHEHEH I BOUGHT YOUR LUNCH FOR YOU! LOKI'D!"
Person 1: "Can you believe Joss Whedon's April Fools prank? He never actually intended on telling us what Loki's army consisted of"
Person 2: "I know! He's such a troll! We totally got LOKI'D!"