No, I didn't find the key. I just got this info from this transaction https://blockchain.info/it/tx/ecc8c09284a6f9e6d52cccf7f8f4aef1d0c4a33984375dea4cea70923066078d on blockchain that moved for the first time funds from that address.
You lost me here. You were asked about the private key, and you are saying you got it from transaction information?!? What am I missing here?
From the transaction I got the public key related to the address 1LzhS3k3e9Ub8i2W1V8xQFdB8n2MYCHPCa.
You can get the private key from a public key only if you know already that the private key lies in a very limited range (in this case from 2^54 to 2^55)
Can you please explain the method you were using to accomplish this magic? 2^55 - 2^54 = 1.8 x 10^16, that's a lot of private keys to check by brute-forcing them. What you are claiming doesn't make sense at all.