SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '518d2c013be7bbc5b71f583e2c410dc47fd15958ef0426da973b96cd7a4c332f' 
  AND token = 'dSmR8MpIoMZDLs8SC/K89LNFwGtzQAJfC07zuS0W6NY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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