SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '808dab86e6a001e8552f8b2bcce5025f268bbe171073065b878f0769dac8dedb' 
  AND token = '3t4vyGnnWIAUuyA34ZgU8OdC7cdINYfsWkMaUvwiycw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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