SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '19b4fb645442de3f41c78d79d54c684ed8d22661962cb933cc274284dfae83f0' 
  AND token = 'CEYOkJE/TcjQFEW/MKtn68IBM33yn/pTCelAvRzG3U8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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