SELECT 
  cscart_banners.banner_id, 
  cscart_banners.type, 
  cscart_banners.target, 
  cscart_banners.status, 
  cscart_banners.timestamp, 
  cscart_banner_descriptions.banner, 
  cscart_banner_descriptions.description, 
  cscart_banner_descriptions.url, 
  cscart_banner_images.banner_image_id 
FROM 
  cscart_banners 
  LEFT JOIN cscart_banner_descriptions ON cscart_banner_descriptions.banner_id = cscart_banners.banner_id 
  AND cscart_banner_descriptions.lang_code = 'en' 
  LEFT JOIN cscart_banner_images ON cscart_banner_images.banner_id = cscart_banners.banner_id 
  AND cscart_banner_images.lang_code = 'en' 
WHERE 
  1 
  AND (
    cscart_banners.type != 'G' 
    OR cscart_banner_images.banner_image_id IS NOT NULL
  ) 
  AND cscart_banners.status = 'A' 
ORDER BY 
  cscart_banners.timestamp desc 
LIMIT 
  0, 6

Query time 0.00178

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "7.20"
    },
    "ordering_operation": {
      "using_filesort": true,
      "nested_loop": [
        {
          "table": {
            "table_name": "cscart_banners",
            "access_type": "ref",
            "possible_keys": [
              "status"
            ],
            "key": "status",
            "used_key_parts": [
              "status"
            ],
            "key_length": "3",
            "ref": [
              "const"
            ],
            "rows_examined_per_scan": 2,
            "rows_produced_per_join": 2,
            "filtered": "100.00",
            "index_condition": "(`pankajecarter_systemfour`.`cscart_banners`.`status` <=> 'A')",
            "cost_info": {
              "read_cost": "2.00",
              "eval_cost": "0.40",
              "prefix_cost": "2.40",
              "data_read_per_join": "1K"
            },
            "used_columns": [
              "banner_id",
              "status",
              "type",
              "target",
              "timestamp"
            ]
          }
        },
        {
          "table": {
            "table_name": "cscart_banner_descriptions",
            "access_type": "eq_ref",
            "possible_keys": [
              "PRIMARY"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "banner_id",
              "lang_code"
            ],
            "key_length": "9",
            "ref": [
              "pankajecarter_systemfour.cscart_banners.banner_id",
              "const"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 2,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "2.00",
              "eval_cost": "0.40",
              "prefix_cost": "4.80",
              "data_read_per_join": "3K"
            },
            "used_columns": [
              "banner_id",
              "banner",
              "url",
              "description",
              "lang_code"
            ]
          }
        },
        {
          "table": {
            "table_name": "cscart_banner_images",
            "access_type": "eq_ref",
            "possible_keys": [
              "banner"
            ],
            "key": "banner",
            "used_key_parts": [
              "banner_id",
              "lang_code"
            ],
            "key_length": "9",
            "ref": [
              "pankajecarter_systemfour.cscart_banners.banner_id",
              "const"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 2,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "2.00",
              "eval_cost": "0.40",
              "prefix_cost": "7.20",
              "data_read_per_join": "32"
            },
            "used_columns": [
              "banner_image_id",
              "banner_id",
              "lang_code"
            ],
            "attached_condition": "<if>(found_match(cscart_banner_images), ((`pankajecarter_systemfour`.`cscart_banners`.`type` <> 'G') or (`pankajecarter_systemfour`.`cscart_banner_images`.`banner_image_id` is not null)), true)"
          }
        }
      ]
    }
  }
}