SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd6b23414c0b67cda6f48b4f87efdc34b8967af8f44227d3d11dd24eefa3966de' 
  AND token = 'ZqpQrTfrKX7fEk0ng0sA00XIOoNbotX1hhO/XVYyRwM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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