SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bde6ee65bd1122a42e7efd2944c4b72451b48b345d13fef002fda91283bbac95' 
  AND token = 'ISTjtSWIsAzYyNWF8qjiytzxw0TV8S+T2qAhfOYyTqw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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