SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49c72789c8ccec791c2d9d0e5b731203911cad1079ba33038417af246c474431' 
  AND token = 'wNt5iHRCE9F6MJMS4e289K09aotKgmklDvtTivc6w1s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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