1. Ask for a raise. Your company likely has some kind of review cycle and there are times in the financial year when employees can get a pay review. Make sure that before that moment comes around you've had a conversation about salary with your direct manager and you're on track to get a raise. Since you know other people's salaries, you can ask for specific numbers instead of asking for a raise in the general sense.

2. Don't focus too much on other people when you're having these conversations. Since you're performing well and have never had a compensation review, it's reasonable to just ask for a raise even without the knowledge of other people's salaries. It might be reasonable to say that you're looking for a salary that's in line with what the rest of the team is making (but I certainly wouldn't start with this). Whatever you do, don't discuss other people's deservingness and don't badmouth anyone.

3. Since you're comfortable financially, you always have the option to quit and find another job. For the same reason you might be less likely to quit because of salary. So if you don't get what you want, it really comes down to your personal priorities about what aspects of your job matter to you and no one else can really give you good advice on that.