SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '97a572804a32457f6f951d351fdebf55d88c750f7dd366ec427a7cb329044964' 
  AND token = 'PTNiyVxabh8g9Eu6aGA+IjP0pUXyIhkzvn6WOErzlzs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}