Rust uses all zero-cost abstractions except for bounds checking and integer overflow checking, so no language can be faster than Rust (assuming equal quality implementations) unless it either isn't memory safe or it can statically prove bounds more frequently, which pretty much requires dependent types (but current languages with dependent types box everything AFAIK so they are terrible performance-wise).

Mojo seems to not only not lack dependent types but also lack first-class references with lifetimes and no lifetime kind, only having borrowed function arguments.

So the answer is no, it is going to be slower since some patterns cannot be expressed and would require costly abstractions.

For example, it looks like that in Mojo an hash table lookup requires to copy the value, while Rust just returns a reference to the value inside the hash table, which it can do since it can express that the return value has the same lifetime as the self parameter because Rust has first-class lifetimes and references (although in this case they can be elided).