SELECT 
  product_id 
FROM 
  cscart_product_popularity 
WHERE 
  product_id IN (
    48996, 48995, 48994, 35250, 35251, 48992, 
    48993
  )

Query time 0.00093

JSON explain

{
  "query_block": {
    "select_id": 1,
    "nested_loop": [
      {
        "table": {
          "table_name": "cscart_product_popularity",
          "access_type": "range",
          "possible_keys": ["PRIMARY", "total"],
          "key": "PRIMARY",
          "key_length": "3",
          "used_key_parts": ["product_id"],
          "rows": 7,
          "filtered": 100,
          "attached_condition": "cscart_product_popularity.product_id in (48996,48995,48994,35250,35251,48992,48993)",
          "using_index": true
        }
      }
    ]
  }
}

Result

product_id
35250
35251
48992
48993
48994
48995
48996