SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47ab0af27571a99f02e4fd82d1be50d1032022413dd0fcccdb20fa5d66fe5b45' 
  AND token = 'TyOcVrkqmG3BFgip7qHwUfttcBARXRh7cUUIpC4hAJM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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