FREDERICK Constant goes distance as Keys top Cannons FREDERICK Right -hander Andres Constant pitched his second complete-game victory of the year to lead the Frederick Keys past the Prince William Cannons, 7 7-3, last night in a Class A Carolina League game. Constant (8-3) scattered five hits and three walks, striking out seven. Two of the five hits off Constant were bases-empty home runs by Cannons third baseman Don Sparks. The Keys broke a 1-1 tie in the third when Scott Meadows led off with a triple, the first of three on the night for Frederick. After Cannons starter Mark Marris (6-6) walked Ken Shamburg,