Generally, dry fasting is thought of as a rest and repair mode. I’ve never seen it practiced or recommended with intense physical activity. Probably best for your rest days, I couldn’t imagine practicing muay thai and starving yourself of water at the same time.
keep in mind that there’s the very high chance that you kick your body into glyconeogenesis because fat metabolism won’t be able to keep up with your energy needs during workout. So, you might temporarily fall out of ketosis due to the sugar produced in your body and put strain on your muscles and organs as you force your body to metabolize them for energy.