SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a8d5be7ce12ec76f773e9a51b9a30f87f26d91a0137be9a00345b554d7d76828' 
  AND token = '22gYUzMBwX4u8WycUQy/yXoqGOKlkczZM4A9Wbums80=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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