ELMONT, N.Y. - If trainer Bill Mott needed a sign to know how Royal Delta was doing as he prepares her for the second half of the year, he got it on Monday when the two-time champion put in a most impressive five-furlong workout over Belmont’s main track. Royal Delta, under regular exercise rider Rodolphe Brissett, worked five furlongs in 58.96 seconds, with a final quarter in 22.47. She galloped out six furlongs in 1:11.45. Royal Delta, who finished 10th in the Dubai World Cup on March 30, is pointing to the Grade 2, $175,000 Fleur de Lis Handicap at Churchill Downs on June 15. That was the same race Royal Delta won last year by eight lengths after finishing ninth in the Dubai World Cup. Mott, who subscribes to the theory that “fast horses work fast,” said he was glad to see Royal Delta on her game. “I’m not disappointed in the way she went,” Mott said.