They are unconstitutional because government does not have the right to set a minimum or maximum hourly rate of pay. Any law that “allows” it is invalid and not binding.
Other invalid laws: Affirmative action, draft registry for men only, requirement that men who pretend to be women can play on a woman’s team. Asset “forfeiture.” Minority setasides. Race quotas. College admission based on race.
Congress quit following the 18 enumerated powers decades ago. Now, look where we are.