如何对sql进行优化？

sql：`sql
SELECT
COUNT(0)
FROM
(SELECT

t1.id,
t1.channel_guar_starus,
t1.user_agen_id,
t1.house_type,
t1.province_code,
t1.city_code,
t1.area_code,
t1.ask_price_type,
t1.data_source,
t1.one_pay,
t1.user_id,
t1.org_id,
t1.guar_no,
t1.total_price,
t1.room_area,
t1.total_price_small,
t1.total_price_big,
t1.credit_loan_small,
t1.credit_loan_big,
t1.rate_small,
t1.rate_big,
t1.lend_cycle_small,
t1.lend_cycle_big,
t1.guar_type,
t1.community_name,
t1.building_name,
t1.house_name,
t1.address,
t1.building_type_name,
t1.end_time,
t1.remark,
t1.reject_remark,
t1.build_year,
t1.lock_status,
t1.order_begin_time,
t1.order_end_time,
t1.create_time,
t1.create_by,
t1.modify_by,
t1.modify_time,
t1.validate_state,
u.login_name,
su.user_name,
u.agent_code,
ci.area_name,
t1.first_remark,
t1.second_remark 

FROM

ha_t_channel_guar t1 
LEFT JOIN ha_t_user u 
  ON t1.user_agen_id = u.id 
LEFT JOIN sys_user su 
  ON t1.MODIFY_BY = su.id 
LEFT JOIN sys_area ci 
  ON t1.city_code = ci.area_code 

WHERE 1 = 1

AND t1.VALIDATE_STATE = '1' 
AND EXISTS 
(SELECT 
  1 
FROM
  LOAN_VMDATA_PRIV vmd1 
WHERE (
    vmd1.OWNER_ID = t1.OWNER_ID 
    OR vmd1.ORG_ID = t1.ORG_ID
  ) 
  AND vmd1.USER_ID = ?) 

ORDER BY t1.id DESC) total