In [1]: d = {f"x{i}": i for i in range(50)}

In [2]: s = {f"x{i}": i for i in range(50)}

In [3]: %timeit s.keys() <= d.keys()
569 ns ± 4.71 ns per loop (mean ± std. dev. of 7 runs, 1,000,000 loops each)

In [4]: %timeit all(p in d.keys() for p in s)
1.93 μs ± 32.8 ns per loop (mean ± std. dev. of 7 runs, 1,000,000 loops each)