SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f449167ac6ffbc2089b08d492ceb2f0c30c912cf6545da3fc53c230ba2c0f84' 
  AND token = 'HKDRw8Z4csfpGSnBKdH271BUj5ibruebF/anlkrJSjc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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