Lyrics with English translation courtsey HappySing:

… The Lyrics 

Aisi uljhi nazar unse hatt ti nahi
Daant se reshmi dor katt ti nahi
Umr kab ki baras ke safaid ho gayi
Kaari badri jawani ki chhatt ti nahi
Wallah ye dhadkan bhadne lagi hai
Chehre ki rangat udne lagi hai
Darr lagta hai tanha sone mein ji
Dil to bachcha hai ji
Dil to bachcha hai ji
Thoda kaccha hai ji
Haan dil to baccha hai ji

Kisko pata tha pehlu mein rakha
Dil aisa paaji bhi hoga
Hum to hamesha samajhte thhey koi
Hum jaisa haaji hi hoga
Hai zor kare, kitna shor kare
Bewajah baaton pe aienwei gaur kare
Dil sa koi kameena nahi
Koi to roke, koi to toke
Iss umr mein ab khaoge dhokhe
Darr lagta hai ishq karne mein ji
Dil to bachcha hai ji…

Aisi udaasi baithi hai dil pe
Hassne se ghabra rahe hain
Saari jawani katra ke kaati
Piri mein takra rahe hain
Dil dhadakta hai to aise lagta hai woh
Aa raha hai yahin dekhta hi na ho
Prem ki maare kataar re
Tauba ye lamhe katt te nahi kyun
Aankhon se meri hatt te nahi kyun
Darr lagta hai mujhse kehna na ji
Dil toh bachcha hai ji…

… And The English Translation:

My eyes are locked such that they don’t move from over her,
While (the age is such that) I am unable to cut a silk thread with my teeth,
I was old long back and my hair are white now,
(but) the black clouds of youth don’t want to go.
O God, my heartbeat is raising,
the colour of my face is going (that means I am ageing)
I am afraid of sleeping alone,
(My) heart is (still) a child,
it’s a bit coward,
yeah, my heart is still a child..

Who knew that the heart, so close to me, could be such scoundrel,
I always thought it would be a pure soul like me only,
it gives so much importance (to things), makes so much noise,
keeps track of useless things,
there is no one as mean as the heart,
someone stop it, someone check it,
I’ll be cheated in this age,
I am afraid to love..
My heart is still a child..

My heart is so sad, I am fearing even while laughing,
I passed my entire youth away (from love),
And now I am meeting (her) in old age,
When the heart beats, I feel-
she is coming here only, but not looking (at me),
It’s hitting me with the knife of love,
Oh my.. Why don’t these moments pass,
Why don’t they move away from my eyes,
I am feared, don’t tell me,
My heart is still a child,
It’s a bit coward,
Yeah, my heart is still a child…