I want to Optimize the Query below. I don't have expertise on optimization techniques.
Please suggest me something which can help me to Optimize the query below :

```
SELECT 
       ad.towncity,
       ad.state,

FROM   promptdescription pd,
       osquestion osq,

WHERE  acc.status = 1
AND    acc.customer_id = con.customer_id
       ap.os_id
AND NOT EXISTS (SELECT 1
                FROM   osquestion osq2,
                       orderedproduct op3
                WHERE  osq2.ext_quest_id = pd.id
                AND osq2.question_id > osq.question_id

```