SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69856541b2bc3d432cf0eb1ad886ab03117362e85dbf5a9c503a6a12d9b42997' 
  AND token = 'OBF8mGyvY9CZnEw6oePntgFq+rSFQEPcQSXpnF97qXk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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