SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '6293a75482ccf95a8ce58ee385ac3cda94f343d2a10fe58f0d95a6063333d9ff' 
  AND token = 'SNMXclBttAZ/8cnntc6uWOdFRijfZ9ul5U47BMm4iKY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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