Slow sort MySQL records by distance

gistfile1.sql

  SELECT 
    name, 
     ( 3959 * acos( cos( radians({$lat}) ) * cos( radians( latitude ) ) 
     * cos( radians(longitude) - radians({$lng})) + sin(radians({$lat})) 
     * sin( radians(latitude)))) AS distance 
  FROM {$table} 
  HAVING distance < 1
  ORDER BY distance