The database in which you can check if you have a valid MTPL or not is called CEDAM and is administered by the Insurance Supervisory Commission (CSA). How are things going? Is simple. After the policy has been concluded, it is reported by the insurer (Attention, insurer, not by the broker) to the CSA. Because the IT system is not well set up, you will not be able to see immediately if it is on the basis of Cedam, because this reporting of the insurer to the Commission can take up to 3 weeks.
But what you have to keep in mind is that the system is not perfect and you may sometimes find erroneous information, which is why on their website you have the "error reporting" section where you can draw attention if the car is insured with a company other than the one you know was issued or if it still doesn't appear as insured even though 3 weeks have passed.
People are often reluctant to fake, especially when talking about rca insurance , where many who want to get rich have destroyed the confidence of insurers by playing the role of authorized issuer.
Lately, however, things have begun to change, the field to be somewhat better regulated and as everything is now operated electronically it is easy to separate a fake issuer from an authorized one.