SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc9ce6f08dbf2ae447814427df7bd2e69b29e70ce6be92d11aaf2fad7b7185b8' 
  AND token = '/5LGjpmicbbIMJFxUxGRW/GMYTkg5DYckoi4LZd0rZU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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