It's an odd term. Can any state be a superpower before modern times? Lyman Miller defines a superpower as "a country that has the capacity to project dominating power and influence anywhere in the world, and sometimes, in more than one region of the globe at a time, and so may plausibly attain the status of global hegemon".

Under that definition, it's impossible for any superpower to exist until relatively recently. Modern technology has made it far easier to project power. That's why I hesitate to call the British Empire a superpower. In a world without phones, airplanes, and instant communication, is a superpower even possible? Would a superpower have shared power during the age of imperialism?

Is Economic dominance necessary? The United States economy passed the British economy around 1870.

In my opinion, there are two options. Either the British Empire post-Napoleon or the United States & USSR post World War II. The Soviet Economy was never particularly close to the American economy though. Is it possible for a superpower to exist when it is not far and away the most powerful state to exist?

The United States since the fall of the USSR has probably been the most dominant state in human history.

A lot of people use the term Great Power. The first Great Power would come far earlier than the first superpower. I don't know enough about Ancient History to go back that far.