SELECT 
  cscart_shippings.*, 
  cscart_shipping_descriptions.shipping, 
  cscart_shipping_descriptions.description, 
  cscart_shipping_descriptions.delivery_time 
FROM 
  cscart_shippings 
  LEFT JOIN cscart_shipping_descriptions ON cscart_shipping_descriptions.shipping_id = cscart_shippings.shipping_id 
  AND cscart_shipping_descriptions.lang_code = 'vi' 
WHERE 
  cscart_shippings.shipping_id = 6

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "const_condition": "1",
    "table": {
      "table_name": "cscart_shippings",
      "access_type": "const",
      "possible_keys": ["shipping_id"],
      "key": "shipping_id",
      "key_length": "3",
      "used_key_parts": ["shipping_id"],
      "ref": ["const"],
      "rows": 1,
      "filtered": 100
    },
    "table": {
      "table_name": "cscart_shipping_descriptions",
      "access_type": "const",
      "possible_keys": ["PRIMARY"],
      "key": "PRIMARY",
      "key_length": "9",
      "used_key_parts": ["shipping_id", "lang_code"],
      "ref": ["const", "const"],
      "rows": 1,
      "filtered": 100
    }
  }
}