[mvdgaag]

Any game that allows mixed strategies has an optimal strategy, so yes, it exists.
As others have pointed out it is a holy grail not worth looking for. Optimal play does a terrible job maximising profit in about any game you can find on earth. I don't know about high stakes though. It is good to know what strategies are suboptimal and how to exploit them, because thats how you make a lot more money than playing optimal.