SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f1ae8df74d2dd140417dbf0690cb96bec2cbf1a487e960a493b56044b28c4b9' 
  AND token = 'NhNQ9HHsWLCJl0uO8HwwgMoJ0Glby8pa+2EHEMaX0PU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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