SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b8e690379e0223d99539ff8a89c28f6c9e6cf9253abd272d81fd5efd71f5cd2a' 
  AND token = 'TdlR1wguEjVLwcrk7TcLypKNiyoo+70zw7Vf6cWo3qo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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