Need Alternative API for better performance

Summary:
Improvement in response time from 2 seconds to milliseconds

Content (please ensure you mask any confidential information):

Using below API we are trying get ItemNumber based on provided criteria, we are receiving expected results with 2-3 sec of response time, but we need response time in milliseconds. Can you provide an alternative API for the same API we are trying to get the response.

API:

https://************.oraclecloud.com:443/fscmRestApi/resources/11.13.18.05/itemsV2?q=Keyword=12;ItemClass=Capture Request&fields=ItemNumber

Response:
{
"items": [
{
"ItemNumber": "DOC-******",
"links": [
{ ....................