The two men reportedly entered the restaurant, located at 2475 Olivera Road, at 12:22 p.m.
The tall man reportedly pointed a handgun at customers and employees while the short man went behind the counter and had the manager give him cash from the register, Cerletti said.
The pair then left the restaurant, ran across the street to Flamingo Drive and got into a black, four-door 1980s Nissan Maxima. The car, which was described as dirty, was being driven by a woman.
The vehicle was seen fleeing on Flamingo Drive toward Thunderbird Drive, Cerletti said.
Witnesses described the first suspect as a black man between 6 feet and 6 feet 5 inches tall with a skinny or thin build. He was wearing a black or dark blue hooded sweatshirt and baggy blue jeans. He was armed with a black handgun, Cerletti said.
The second man was described as a black man between 5 feet 2 inches and 5 feet 4 inches tall with a medium build. He was wearing a blue ski mask with only his eyes showing, a black jacket and blue jeans.
Witnesses were unable to describe the getaway driver other than saying she was a black woman.
Concord police searched the area and put out a countywide alert, but were unable to find the suspects, Cerletti said.