请教mysql查询优化

PHPstupid

    select DISTINCT a.employee_id,a.account,a.account_state,c.created_date as account_effect_date,c.phone,c.employee_name,b.mobilebureau,d.company_shorter_name,
        e.use_cycle,e.eff_type,e.service_desc,e.create_date,e.result_code,e.item_value,e.personpayflag,e.result_msg
                    from t_employee_account a left join t_system_employee c on a.employee_id=c.employee_id left join t_company d on a.company_id=d.company_id
            left join t_mobilenumber_head b on a.account LIKE CONCAT(b.numberhead,'%') left join tbl_ngec_request e on a.account = e.account

t_employee_account  和 t_system_employee  是用户表，根据employee_id关联
t_mobilenumber_head  是存放号段的，根据t_employee_account 中的手机号（account）得到运营商（移动、联通、电信）

目前这条语句查询非常吗，请教要如何优化？