SELECT 
  page 
FROM 
  ushop_page_descriptions 
WHERE 
  page_id = 21 
  AND lang_code = 'es'

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}