SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f00f9b8112e81eb3eff033ad9f955236ec8be8479cfacf0dc392baeee812aa1b' 
  AND token = 'PBjx9I0sPtmBtOzjs8TreC01MfSovE/UORAzlDkShlM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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