SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '25433402155498a57375ba71707dd2724fb1b50182380630010f0c6b7f5f4996' 
  AND token = 'ptdbyrqBdC+EMEQvKMRO8u5xmUaXj3sE9XjheYQJtMw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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