Just saw this crack in my tire, don’t like the look of it. Is it still fine?
It’s okay. It happens, but it also means your tyre is approaching its end of life. It may last for a few weeks to many months, depending on how often you use the bike and how much strain you put on the tyre (pressure, weight, bumps, etc.)
It you don’t use your bike at all it will fail quickly. It you use it everyday it will hold until your tyre runs out.
In any case, if the tyre becomes herniated (big bump on the side) stop using your tyre at once and change both the tyre and the tube. As for now : don’t worry, it’s fine.