SELECT 
  redirect_id, 
  src, 
  type, 
  object_id, 
  dest, 
  lang_code 
FROM 
  cscart_seo_redirects 
WHERE 
  src = '/why-you-should-sell-on-ebonza-marketplace/we-got-the-best-tracks-of-legendary-b-b-king-demo-en-5'

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "nested_loop": [
      {
        "table": {
          "table_name": "cscart_seo_redirects",
          "access_type": "ref",
          "possible_keys": ["src"],
          "key": "src",
          "key_length": "767",
          "used_key_parts": ["src"],
          "ref": ["const"],
          "rows": 1,
          "filtered": 100,
          "index_condition": "cscart_seo_redirects.src = '/why-you-should-sell-on-ebonza-marketplace/we-got-the-best-tracks-of-legendary-b-b-king-demo-en-5'"
        }
      }
    ]
  }
}