Without seeing the game it is difficult to say exactly why you obtained such moderately high score. But I can give some general you comments based on how accuracy is calculated by chess.com.
Chess.com use a statistical model (not revealed) to calculate accuracy. However, it is more complex than calculating the proportion of best moves. By what they say, probably there is some kind of weighting that takes into account how near your move is to the best computer one.
Of course the higher rated you are, the higher your accuracy. And GM's get accuracies much above 90%. Now, that said, you could have a high score and still lose: a blunder is enough to lose the game.
Finally, I can think of of some factors that might contribute to having relatively high scores:
- Following correctly long theoretical lines in the opening.
- In certain endings it is difficult to go wrong.
- In a quiet position, if you don't blunder a piece, any other move probably will be OK (suggested by @Hauke Reddman).