SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6ca95ec712fc237758e6239c3713f89792a05dc6134eecd33e242c6c5ee5c90a' 
  AND token = '7ZHJY1Y374YFzdf2FZQAwELllK+WJpUfWrV6vpqca7Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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