SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'ddc3660572c649533b88cef35d451c73c2131f96a0dd1799950db68aaa7ddc22' 
  AND token = 'AYd5drZMYWX1kC0NNO0XtTswW4U0IziCJa4jaJMrk0U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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