I am working in a very reputable company and by the grace of Allah, I am very good at my job. But for getting this job, I lied a little in my CV which was not even necessary. Is my earnings Haram? If so, will my prayers, fasting and other Ibada be rejected?

Praise be to Allah, the Lord of the World; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.

Lying is severely forbidden; it is a way of dissoluteness. It is narrated in Sahihain and other references of Hadith that the Prophet (Sallallahu Alaihi wa Sallam) said: "Truthfulness leads to righteousness, and righteousness leads to Paradise. And a man keeps on telling the truth until he becomes a truthful person. Falsehood leads to Al-Fujoor (i.e. wickedness, evil-doing), and Al-Fujoor (wickedness) leads to the (Hell) Fire, and a man may keep on telling lies till he is written before Allah, a liar" .
In addition, the resume requested by a company has many effects as far as the benefits and goals of a company are concerned. Therefore, giving wrong information in a resume, besides lying, involves cheating and deceiving too.
The Prophet (Sallallahu Alaihi wa Sallam) said: "He who deceives is not of us" [ Abu Dawood and others].
Therefore, my questioner brother, you should repent towards Allah and make clear to the authorities the reality about your C.V. If they accept it: good; otherwise, there is no good in earnings through unlawful means. Also, you should ask pardon from them for what has happened.
As for your forms of worship such as prayers and other matters, if you perform them as required in Shari'a they are correct and sufficient. Whether they are accepted or not is matter related only to Allah; no one else can know.
Allah knows best.