Chrome on Android has credit card scanner in both autofill and PaymentRequest. For autofill, Chrome must detect your input field to be credit card number for this option to show up. Try this form:
Credit card number: <input autofocus="" type="text" name="CCNo"><br>
Name on card: <input type="text" name="name"><br>
Expiry Date: <select name="CCExpiresMonth">
<option value="01">01</option>
<option value="02">02</option>
<option value="03">03</option>
<option value="04">04</option>
<option value="05">05</option>
<option value="06">06</option>
<option value="07">07</option>
<option value="08">08</option>
<option value="09">09</option>
<option value="10">10</option>
<option value="11">11</option>
<option value="12">12</option>
</select>
/
<select name="CCExpiresYear">
<option value="2016">2016</option>
<option value="2017">2017</option>
<option value="2018">2018</option>
<option value="2019">2019</option>
<option value="2020">2020</option>
<option value="2021">2021</option>
<option value="2022">2022</option>
<option value="2023">2023</option>
</select>
<br>
CVC: <input name="cvc">
<br>
<input type="reset" value="Reset">
<input type="submit" value="Submit">
</form>
Be sure to host this form over HTTPS.