How to find the nearest lat and lang in postgresql

I am trying find the nearest lang and lat from the specified lat and lang i tried the below mentioned query, in my query i have mentioned the place muscat's lat and lang ,so i want to display the nearest cities of muscat with limit 3 along with muscat

CREATE TABLE IF NOT EXISTS tablename(_id SERIAL NOT NULL UNIQUE PRIMARY KEY,city VARCHAR, Lat NUMERIC, Lang NUMERIC);

select * from (
SELECT  *,( 3959 * acos( cos( radians(6.414478) ) * cos( radians( lat ) ) * cos( radians( lang ) - radians(12.466646) ) + sin( radians(6.414478) ) * sin( radians( lat ) ) ) ) AS distance 
FROM tablename
) al
where lat >  23.61  OR lang >  58.54
ORDER BY distance
LIMIT 1;

here is my table (Assumed data not exact lat and lang)data

| id | City      |  lat      | lang    |
----------------------------------------
|  1 | muscat    | 23.61     | 58.54   |
|  2 | sur       | 22.566    |59.52    |
|  3 | Muhafazat |23.585     |58.40    |
|  4 | ZZZ       | 5.8       | 7       |
|  5 | AAA       | 9.22      | 5       |
|  6 | Barka     |23.613     |58.592   |

Expected out put:

    | id | City      |  lat      | lang    |
    ----------------------------------------
    |  1 | muscat    | 23.61     | 58.54   |
    |  2 | sur       | 22.566    |59.52    |
    |  3 | Muhafazat |23.585     |58.40    |
    |  6 | Barka     |23.613     |58.592   |