SELECT 
  * 
FROM 
  cscart_vd_vendor_images 
WHERE 
  brand_id = 210 
  AND image_type = 'A'

Query time 0.00055

JSON explain

{
  "query_block": {
    "select_id": 1,
    "nested_loop": [
      {
        "table": {
          "table_name": "cscart_vd_vendor_images",
          "access_type": "ref",
          "possible_keys": ["brand_id"],
          "key": "brand_id",
          "key_length": "4",
          "used_key_parts": ["brand_id"],
          "ref": ["const"],
          "rows": 5,
          "filtered": 100,
          "attached_condition": "cscart_vd_vendor_images.image_type = 'A'"
        }
      }
    ]
  }
}

Result

id brand_id image_type image_path image_name image_size image_type_mime
996 210 A images/vendor_directory/210/Usagi 1.jpg Usagi 1.jpg 280789 image/jpeg
997 210 A images/vendor_directory/210/Usagi 2.jpg Usagi 2.jpg 241816 image/jpeg
998 210 A images/vendor_directory/210/Usagi 3.jpg Usagi 3.jpg 314980 image/jpeg
999 210 A images/vendor_directory/210/Usagi 4.jpg Usagi 4.jpg 200344 image/jpeg