Mysql 添加索引后查询花费的时间太长

添加索引后，查询花费的时间太长

    SELECT bc.billabletreatmentsetup_id, bs.name, IFNULL(bc.charges_for,'OPD') 
    as charges_for_vals, bc.nc_applicable, bc.unit_value, bc.taxtype_id, bc.id, bc.amount, bc.effective_date 
    FROM billabletreatmentcharges bc, billabletreatmentsetups bs 
    WHERE bs.id = bc.billabletreatmentsetup_id 
    AND bs.status='Active' 
    AND bs.branch_id = '9197651b-e2b9-1924-b931-54f13cfc31c0' 
    AND bs.deleted=0 
    AND ( bc.billabletreatmentsetup_id, bc.effective_date, bc.date_modified, IFNULL(bc.charges_for,'OPD') ) 
    IN ( 
        SELECT billabletreatmentsetup_id, max( effective_date ) , max( date_modified ), IFNULL(charges_for,'OPD') 
        FROM billabletreatmentcharges 
        WHERE effective_date <= '2015-03-12' 
        AND insprovider_id IS NULL GROUP BY billabletreatmentsetup_id, charges_for 
       )
    AND bc.insprovider_id IS NULL ORDER BY bs.name, bc.charges_for ASC

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请给你的问题增加一点背景。你的数据库管理系统是什么？表格描述是什么。是什么原因导致延迟索引的。。。什么能让它消失？这些细节将帮助其他人回答这个问题。我使用的是mysql，我有三个表billabletreatmentgroups，billabletreatmentsetups&BillableTreatmentCharges billabletreatmentgroups的主键是billabletreatmentsetups的外键和主键billabletreatmentsetups是BillableTreatmentCharges的外键请解释[查询]以检查可能的瓶颈