Two of the men, one armed with a long-barrel revolver, entered the store at about 12:50 p.m., Nassau County police said, while the third man waited outside in a red -- or possibly maroon -- Mitsubishi.
Store employees managed to lock themselves in the store office, police said. Police said the would-be robbers then spent about a minute in the store, but fled empty-handed.
No one was injured, police said.
Police said the suspect armed with the handgun wore a hooded shirt, blue jeans and a black ski mask. The second suspect who entered the store wore a Mets hat, as well as large sunglasses, a blue sweatshirt and jeans, police said.
No description was available for the third suspect.
Police are asking anyone with information about the attempted robbery to call Crime Stoppers at 800-244-TIPS. All calls will remain confidential.