SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b1844c6f362871dec334190246a6bb44e7a2b0050fb8ba80716ddf7f21ed642' 
  AND token = 'CBZR0E0xLupji83K72HdUSJdIpeR9E+7ECukMaoJeWQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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