The song title is a reference to Sanford and Son, a popular television sitcom from the 70s. Fred Sanford, a character from the show, would always mention El Segundo as a joke, like “Godzilla Eats El Segundo!” for example.
Q also tells us this in the movie/documentary Beats, Rhymes & Life: The Travels of A Tribe Called Quest.
El Segundo is a part of LA county in California.