Speed of light in a vacuum is 186,000 miles per second. Internet backbone is fiber, light travels slower in fiber about 70% the speed in vacuum or about 130,000 miles per second.
Ping measures round trip time. New York city to LA is about 2500 air line miles so round trip is 5,000 miles. Actual fiber optic cable length is significantly longer so figure cable length is probably closer to 6,000 miles.
You do the math.
That is the best possible time based solely on transmission flight time, in the real word other factors will typically add another 25-50 ms.
Still pretty fast when you think about what is actually happening.