I had cramping issues since I started biking 20 years ago. I have been able to almost eliminate them entirely through the following:
#1 conditioning to the demands of the event/race - while you didn’t describe the details of the race, have you done progressive intervals (more and longer) in each of the zones required for the race (i.e. sweet spot, threhold, over/under, VO2)?
#2 electrolytes - I use Hammer Nutrition’s Endurolyte Extremes for both hard interval training rides and races. In addition, for hard events/races and ridiculously hard spirited group rides I will use Hammer’s Race Caps and Anti-fatigue capsules (you can go on their website and read the ingredients and usage).
#3 stretching and rolling - after every workout (and event/race), I do 20-30mins of stretching and rolling. It greatly improves flexibility and muscle recovery.
I’m pretty close to peak condition so cramps are now rare, but as I push myself to new limits I will inevitably have them again until I train further.
btw: On hot summer days during the training rides I mentioned, I did bring along a flask of pickle juice if cramping started and it seemed to help in the moment. What I have described above has been doing the trick during the fall/winter.