SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '98fcd26a09af2638c64e501bc21dde80d1689007f1591fdffead8dedf26fa84d' 
  AND token = 'TCgkdGv9oQPMnXBb1SS8wk/9Ij5S0KxnRit+juw1Qm0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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