Not sure about muesli. In Switzerland we have this option: https://www.ketoshop.ch/collections/konfi-mueesli-aufstriche... but as you can see they are crazy expensive. I tried them once and they definitely taste good, but it is just too much money for me. For my breakfast I go now with natural skyr jogurt with a bit of sweetener blended with a large coffee. And as I mentioned I mostly do intermittent fasting, so I am not super strict about the keto part of the equation.