I would go with
uint64_t ticksOfDuration10ms; // No comment necessary
uint64_t ticksOfDuration10ms; // No comment necessary
You'll almost always have a global variable, preprocessor define... or something similar to get the frequency (or time increase per tick), which you should use whenever you have to convert "ticks" to actual physical units. If the actual effective tick rate is visible at many places in your code, both as a symbol name or as a comment, you are most certainly doing something wrong.
(then you'd know it was safe)