Hanuman is worshipped since ancient times, yes. Hanuman being the son of Shiva comes from Rigveda.
Rudra in rigveda is described as the father of maruts
- प्र ये शुम्भन्ते जनयो न सप्तयो यामन् रुद्रस्य सूनवः सुदंससः ।
- रोदसी हि मरुतश्चक्रिरे वृधे मदन्ति वीरा विदथेषु घृष्वयः ॥
- “Those who adorn themselves, like women, like steeds upon the course, the sons of Rudra, of excellent deeds;
- indeed, the Maruts have made Heaven and Earth grow; the heroic, impetuous ones rejoice in the assemblies.”
There is a 3rd century sculpture of Hanuman in gandhara
5th CE Gupta period