How late can a landing clearance be given?
Short answer: for visual approaches, it is not yet set in EASA regulations, but a draft recommends that the landing clearance be issued somewhere from downwind to short final (dashed line in the diagram below).

The relevant distance I found only applies to radar approaches:

8.9.6.1.7 Clearance to land or any alternative clearance received from the aerodrome controller or, when applicable, the procedural controller should normally be passed to the aircraft before it reaches a distance of 4 km (2 NM) from touchdown.$^1$

As for visual approaches it says:

7.10.1 (...) a landing aircraft will not normally be permitted to cross the runway threshold on its final approach until the preceding departing aircraft has crossed the end of the runway-in-use, or has started a turn, or until all preceding landing aircraft are clear of the runway-in-use.$^2$


Reference: EASA PANS ATM Checklist
$^1$ Transposed from ICAO Doc 4444 as GM3 to AMC2 ATS.TR.160(d)(3)
$^2$ Transposed from ICAO Doc 4444 in various AMCs to ATS.TR.210(c) and ATS.TR.220
A note on EASA regulations: Generally, for air traffic services EASA uses the text of ICAO Doc 4444 as Acceptable Means of Compliance (AMC) to the regulations, hence the transposition here.

A 2017 EASA draft (not yet regulation) discusses where you should ideally receive the landing clearance:

GM5 ATS.TR.210(a)(3) Operation of air traffic control service
DESIGNATED POSITIONS OF AIRCRAFT IN THE AERODROME TRAFFIC AND TAXI CIRCUIT IN RELATION TO AERODROME CONTROL TOWER CLEARANCES
The following positions of aircraft in the traffic and taxi circuits, as shown in Figure 1, are the positions where aircraft normally receive aerodrome control tower clearances. Aircraft should be watched closely as they approach these positions so that proper clearances may be issued without delay. Where practicable, all clearances should be issued without waiting for aircraft to initiate the call.
(...)
— Position 4. Clearance to land is issued here as practicable.
(...)