MySql subquery performance enhancment

subquery-performance.sql

-- enviroment  : Mysql 5.5
-- worst peerformance frist 
--explain query indicate it not depend on any index on partent query ( so it will full scan on table with 11M )

SELECT co_id FROM argo.v_r_p_master WHERE mn_code 
	IN (
		   SELECT pk_data FROM argo.s_r_d_l WHERE insert_date > (NOW() - INTERVAL 1 DAY)
 		   AND table_name IN ('argo.mn_code') AND pk_data IS NOT NULL
 		);
 		
 		
-- CONVERTED TO NEXT QUERY
-- best performance  
-- explain query indicate it not depend on any index on partent query 


SELECT co_id
     FROM ar.p_master pm
          JOIN ar.s_r_d_l srdl
             ON ((pm.mn_code = srdl.pk_data))
    WHERE    srdl.table_name IN ('ar.m_master',
                                  'ar.m_master_new')
          AND  insert_date > (NOW() - INTERVAL 1 DAY)
          AND srdl.pk_data IS NOT NULL;
          
          
-- found link that take about this issue http://bugs.mysql.com/bug.php?id=9021 
-- some enhancment in mysql 5.6 approve subqueries but i am not give it a try