SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6ef1f13a9dad96d4594df4fb09920db28aa091a66e2a406862c364bd2fac5891' 
  AND token = 'uQBoAXNCbM+ZxZehhZoG7PRxvUkZBWIAt3yH2a1vcBU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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