SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '3622e836c30cb3a4034381d5645f9aa3e5502652e83838e22275f15a157c4d89' 
  AND token = 'VWCaCXLJw+G7h/7Big1KaRQJd4HgDBmkbjx2m8o79fI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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