SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '956fcf20310a41827d4d64ba1d161ee96e612f082ba5ec7bf82e9f24d44972bc' 
  AND token = 'igpnQ+OdLrD+0NKcZoMQVIX/EtXvzuqljOgmN1kXGbA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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