SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d0a19bb358f52388fddd2bddf03d2f0335f7560f4170939178b334a92abebcd' 
  AND token = 'huuIQpQxJpDXCfsSTxTlXXebMmZ5AVRVuuRmSQOrWfA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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