SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c46ac6da18c9f804ac6f047d7427cf5736bb98302f4345e8d48ac7368eafd24' 
  AND token = 'VaNpFS/BXcsIGL2ZCTXWJLams+5v6vzJHihu9H6RcPs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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