Is the prayer of one from whom madhy (pre-seminal fluid) is discharged for a long period due to mixing at work valid after performing istinja (washing the private parts) and wudu (ablution)?

Your ablution (wudu) and istinja' (washing of private parts) from pre-seminal fluid (madhy) are valid, and this is the prescribed way, based on the hadith of Ali: "Perform ablution and wash your penis." If the discharge of madhy stops for a time that allows you to perform the prayer before its time expires, then it is obligatory upon you to perform ablution and pray at that time with a valid state of purity; otherwise, your prayer will not be valid. However, if the discharge of madhy continues without interruption, then performing istinja' and ablution and praying is sufficient for you, and your prayer will be valid at that time, and you are not burdened with more than that.