Grant permission to user to execute a Stored Procedure

If you want to allow user to execute Store procedure then use GRANT EXECUTE keyword

Allow user to execute all stored procedure
GRANT EXECUTE ON *.* TO 'user'@'localhost';

Allow user to execute all stored procedure attached with a single database
GRANT EXECUTE ON db_name.* TO 'user'@'localhost';

Allow user to execute a single stored procedure
GRANT EXECUTE ON db_name.sp TO 'user'@'localhost';