SELECT 
  object_id 
FROM 
  cscart_seo_redirects 
where 
  src = '/snacks/page-26' 
  AND type = 'p'

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "0.35"
    },
    "table": {
      "table_name": "cscart_seo_redirects",
      "access_type": "ref",
      "possible_keys": [
        "src"
      ],
      "key": "src",
      "used_key_parts": [
        "src"
      ],
      "key_length": "767",
      "ref": [
        "const"
      ],
      "rows_examined_per_scan": 1,
      "rows_produced_per_join": 0,
      "filtered": "10.00",
      "cost_info": {
        "read_cost": "0.25",
        "eval_cost": "0.01",
        "prefix_cost": "0.35",
        "data_read_per_join": "156"
      },
      "used_columns": [
        "src",
        "type",
        "object_id"
      ],
      "attached_condition": "(`cscart_db`.`cscart_seo_redirects`.`type` = 'p')"
    }
  }
}