SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2639d9748117667a91a21fdfc1e35abd8943e79febb231aa1bdebd160a8eb420' 
  AND token = 'Ht9MF2nOaoJcuSpKFzo5B8UdKTjcNuouxKlL1YTa08s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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