If the very next line is the only one that needs to be (in a loop / after an if), then the { } are not needed.

I feel like it's very close to being a "realistic" code someone might actually write in their everyday work

OP solved it, closing

Yes, for yellow kata it is nothing unusual to expect a solution of some specific complexity class. Many yellow kata still accept solutions of poor complexity, but there are many which have stricter requirements.

Having said that, this particular kata has no special requirements, and slow solutions should still pass. Of your solution was timing out, it either had a bug and fell into an infinite loop, or was exceptionally slow ;)