PREPARE stmt1 FROM
"select ...quite complex select from tenth of tables..
 and `subscribers`.`id` = ?
 group by `subscribers`.`id`
 limit 1";
SET @a = 77586744;
EXECUTE stmt1 USING @a;
DEALLOCATE PREPARE stmt1;

SET @sql = CONCAT("select ...quite complex select from tenth of tables..
 and `subscribers`.`id` = ",77586744,"
 group by `subscribers`.`id`
 limit 1");
PREPARE stmt1 FROM @sql;
EXECUTE stmt1 ;
DEALLOCATE PREPARE stmt1;