SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25a5c7272f3027cfc3986e49aa36dcbb6e5d17db8eab8e851d2e6b6dc8e4780d' 
  AND token = 'CO+WbGL9i+8fHSgYJhuSSYWAig+FArhIR7ylEUGSP7E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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