SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67d6e244433e78fa7f659bfe38a9751fbc2838387608de90f60b0c9c6052a32d' 
  AND token = 'NBe8eFc+uLwiaFz6SZ4G+kSPBZH/JKGmSF0M79W/E2Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}