SELECT 
  * 
FROM 
  cscart_vd_vendors_relationships 
WHERE 
  brand_id = 215

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "nested_loop": [
      {
        "table": {
          "table_name": "cscart_vd_vendors_relationships",
          "access_type": "ref",
          "possible_keys": ["brand_id"],
          "key": "brand_id",
          "key_length": "4",
          "used_key_parts": ["brand_id"],
          "ref": ["const"],
          "rows": 19,
          "filtered": 100
        }
      }
    ]
  }
}

Result

id brand_id feature_id variant_id lang_code
14463 215 661 2198 es
14462 215 649 1924 es
14461 215 648 1905 es
14460 215 654 2140 es
14459 215 654 2136 es
14458 215 647 1890 es
14457 215 662 2211 es
14456 215 662 2210 es
14455 215 662 2205 es
14454 215 662 2202 es
14453 215 660 2188 es
14452 215 658 2183 es
14451 215 658 2179 es
14450 215 652 2106 es
14449 215 652 2121 es
14448 215 652 2114 es
14447 215 646 1887 es
14446 215 653 2128 es