Study helps all openings as far as I know, so I can only tell you which openings might want comparatively more or less study.
The London System, which seldom occurs in my games (so I do not personally know a lot about it), has the reputation of wanting comparatively little study.
[fen ""]
[startflipped "0"]
[startply "5"]
[title "London System"]
1.d4 Nf6 (1...d5 2.Nf3 Nf6 3.Bf4) 2.Nf3 e6. 3.Bf4
The King's Gambit cannot be competently played without any study at all, but with moderate study becomes dangerous and double-edged without being overly formulaic. (Not a few masters have regrettably concluded that the King's Gambit is probably slightly unsound, but this does not necessarily make the King's Gambit a poor opening in submaster play. Anyway, even masters sometimes play it.)
[fen ""]
[startflipped "0"]
[startply "3"]
[title "King's Gambit"]
1.e4 e5 2.f4
If you try for the King's Gambit or for a more sober king's-pawn opening, but 1.e4 c5 happens, then you can steer into the Closed Sicilian with 2.Nc6, which is a quite different kind of game than the King's Gambit but is playable without excessive study.
[fen ""]
[startflipped "0"]
[startply "3"]
[title "Closed Sicilian"]
1.e4 c5 2.Nc3
(Like many players, I usually prefer to play the other knight, 2.Nf3, in Sicilian games, but playing the other knight leads to just the sort of game you wish to avoid.)
If you try for the King's Gambit or for a more sober king's-pawn opening, but 1.e4 e6 happens, then you may be in some trouble. That is called the French Defense and, as far as I know, most lines that follow from it reward study. However, the Exchange Variation, diagrammed below, might be reasonable for you to attempt.
[fen ""]
[startflipped "0"]
[startply "5"]
[title "Exchange French"]
1.e4 e6 2.d4 d5 3.exd5 (3.Nc3)
Probably a little better than the 3.exd5 of the above diagram, yet still not extremely theoretical, is 3.Nc3, which leads to a different kind of game.
The King's Gambit is interesting as far as it goes, but even given 1.e4 e5 most players I know come to prefer less speculative openings. Arguably the most basic, principled such opening is the Ruy Lopez. At the master level, the Ruy Lopez greatly rewards study, but at submaster levels the Ruy Lopez is an inherently sound opening in which straightforward play usually leads to interesting games.
[fen ""]
[startflipped "0"]
[startply "5"]
[title "Ruy Lopez"]
1.e4 e5 2.Nf3 Nc6 3.Bb5
Much better chess players than I am prefer openings I have not even mentioned; so, to be clear, I make no recommendation for or against any of the above openings to the general player. The above openings are recommended to you because you state that you prefer to minimize study time.
I will say this, though. Unfortunately for you, the nature of chess is that, even for a nonmaster, a moderate quantity of opening study goes a long way. Opening study isn't everything, but a moderate quantity of opening study complements almost everything else a chess player tries to do, from midgame tactics to endgame targets. If someday you decide that you have more time and you decide to study openings a little more, why, many nonmasters find such study interesting. You might try it someday, at your discretion.
Meanwhile, if you want a single anti-studying recommendation, then, in light of your stated requirements, go for the Ruy Lopez. If Lopez does not suit, and if you feel certain that you will never change your mind regarding study, then give the London a try. Good luck.