Floyd Mayweather won’t take Jake Paul seriously if he keeps facing MMA fighters past their prime. At 5-0, Paul is unbeaten as a professional boxer and has scored knockout wins over former MMA champions Ben Askren and Tyron Woodley. Notorious for his pursuit of big paydays, Mayweather can appreciate the buzz that the YouTube star has created. But Paul as a boxer? The 45-year-old Hall of Famer Mayweather says it’s easy to look good against fighters who aren’t actual boxers. “Jake Paul, as of right now, for what he’s doing, it’s good for what he’s doing,” Mayweather said in an…