SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'baeac33516947f3783943b5a6892ab27ccd87459b2ebbfe5bceb179c467bfb47' 
  AND token = 'SJ2E8H2tmhk8Rkb7Dn57jDvA0heoLmclJET9sOkSVc8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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