SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c515334f858ea32c0122c33af0f43ddb21e7e8dc2313fc3678a703c06733788' 
  AND token = 'usw2F4TwHnpaiUlIYYTaHQK3gaK6q8r/CJNuCdNGPcw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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