NEW YORK — No mustard. No ketchup. Just a right hand with a hot dog, a left hand with a bun — and a champion’s heart full of sodium. Joey Chestnut won a record 15th Nathan’s Famous International Hot Dog Eating Contest on Monday, scarfing down 63 hot dogs and 63 buns in 10 minutes. Give that man some lemonade! “It was a crazy contest,” Chestnut said after conquering Coney Island’s iconic July 4 event yet again. “I’m happy I was able to come through on top. New York is amazing. There’s no place like it in the world.” With the beach crowd chanting his name — “Jo-ey, Jo-ey, Jo-ey” — Chestnut beat …