SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '68c5713963fe52afcee979cf8540fb8447197bc7b210ec7b7d42d8fa012efddc' 
  AND token = '4TYC/E1ahrZEfD+VuY+7AbJlHt+Sksi7gH88VU3d0Rc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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