Have you already checked this answer python filter files by modified time? Your requirement should be a slight modification to this.
import os
import pandas as pd
from datetime import datetime
from pathlib import Path
search_dir = r"C:\Users\123\Documents\Folder"
os.chdir(search_dir)
files = filter(os.path.isfile, os.listdir(search_dir))
files = [os.path.join(search_dir, f) for f in files] # add path to each file
Till here, your code remains the same. I am not very sure why you need to sort your files as per the time if you will filter them later on. However, assuming this is a necessary step, I have changed the last line as it results in a NoneType result. Instead I use the pathlib library to sort the files as you wanted there. So replace the last line with the following line.
files_sorted = sorted(Path(search_dir).iterdir(), key=os.path.getmtime)
You haven't specified whether your filter time is user provided or a time stamp from a file. If it is a time stamp from a file proceed by calling the time stamp of that file. For example, I take the time of the first file from the sorted file list.
particular_time = os.path.getmtime(files_sorted[0])
Following this, assuming that you want to remove all the files that have times that are lower than the particular time (you didn't clearly mention what you want there again), do the following:
for f in files_sorted:
tLog = os.path.getmtime(f)
print("checking ", f, datetime.fromtimestamp(tLog))
if particular_time > tLog:
print("filter out the files", f)
files_sorted.remove(f)