The Instant AND gate works using somthing dubbed Piston Logic Modules, which, rather than check if a current isnt there, like redstone, can check if it is or isnt, based on how they are set up. then normally consist of a piston, with a solid block on it, and a gravitised block ontop of that, however, this can cause circuits to be large, however, also linear. Even so there are far more compact ways to do it, though theese modules are NOT instant, they have far less tics of delay than a normal logic gate.
Simply by stringing two Logic Modules together we can create an AND effect. This is simpler than older 'instant' models, which primarily used [NOT ((NOT A) OR (NOT B))].