SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a541ab2898ac9d0ee670395b75b6f9219bcea154dc80f423793de289029693d' 
  AND token = 'WNrJLvOqYHlD2AXe8/h3wBABS/+WUmtpznPC6wCfGfU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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