SELECT 
  cscart_et_featured_product_banner_tabs.block_id, 
  cscart_et_featured_product_banner_tabs.status, 
  cscart_et_featured_product_banner_tabs_data.data as q_blocks, 
  cscart_et_featured_product_banner_tabs.data as q_blocks_data 
FROM 
  cscart_et_featured_product_banner_tabs 
  LEFT JOIN cscart_et_featured_product_banner_tabs_data ON cscart_et_featured_product_banner_tabs_data.block_id = cscart_et_featured_product_banner_tabs.block_id 
  AND cscart_et_featured_product_banner_tabs_data.lang_code = 'en' 
WHERE 
  1 
  AND cscart_et_featured_product_banner_tabs.status = 'A' 
  AND cscart_et_featured_product_banner_tabs.block_id = '67'

Query time 0.00105

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "1.00"
    },
    "nested_loop": [
      {
        "table": {
          "table_name": "cscart_et_featured_product_banner_tabs",
          "access_type": "const",
          "possible_keys": [
            "PRIMARY"
          ],
          "key": "PRIMARY",
          "used_key_parts": [
            "block_id"
          ],
          "key_length": "3",
          "ref": [
            "const"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 1,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "0.00",
            "eval_cost": "0.20",
            "prefix_cost": "0.00",
            "data_read_per_join": "24"
          },
          "used_columns": [
            "block_id",
            "data",
            "status"
          ]
        }
      },
      {
        "table": {
          "table_name": "cscart_et_featured_product_banner_tabs_data",
          "access_type": "const",
          "possible_keys": [
            "block_id"
          ],
          "key": "block_id",
          "used_key_parts": [
            "block_id",
            "lang_code"
          ],
          "key_length": "9",
          "ref": [
            "const",
            "const"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 1,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "0.00",
            "eval_cost": "0.20",
            "prefix_cost": "0.00",
            "data_read_per_join": "24"
          },
          "used_columns": [
            "block_id",
            "data",
            "lang_code"
          ]
        }
      }
    ]
  }
}

Result

block_id status q_blocks q_blocks_data
67 A a:1:{s:5:"title";s:27:"Denis Trasporti & Traslochi";} a:5:{s:10:"color_type";s:1:"C";s:5:"color";s:7:"#172a3a";s:9:"bkg_color";s:7:"#172a3a";s:10:"tabs_color";s:7:"#172a3a";s:17:"tabs_color_active";s:7:"#dd403a";}