SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da17ec75e35ce3f6f59754eefd6218e7aba9d39b7ce467a20bebfba0646ec1d7' 
  AND token = 'u3ohsnd3dcOXOURjXb603EPPSYESiVhl8/uHdqewHNA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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