Like Naruto, there is not a determining period of time from which we know where Boruto takes place. That said, it does seem to be an alternate form of Earth and one that has technology that is growing and starting to more resemble what we have today. To answer the question, we do not know if Boruto is in our past but we do know that it is many years after the events of Naruto and there are tricky timeline stuff thrown in there. For one, the opening scene of the manga and anime shows a moment that has not happened yet where Boruto is much older. In a way, that fight that we see is the “present-day” and everything that is happening in the series right now is sort of “set in the past”, showing the events that lead up to that scene. That said, there is also a story arc in the series, and one of the best ones at that, that has to do with the past that I will not spoil too much. So, this is a somewhat complicated question to answer, but Boruto is at least not set in our Earth’s past.