SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '12b17d0f53fb03605f9dcdcec87394d16ab0a1eefe762b4c0a20471e20a2bbe3' 
  AND token = 'w4jcsFl/xZLMhknmmZlFgLUjKNtKlJY+Yqt/rUcx7+o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}