SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0758427dbf29a4d417f03b6dae82fb805fdcfeb0de17b18828ab0ef32ea77a0' 
  AND token = 'jrowFxjVmVZZVvAcqIy2CnX5DDEkCHzkTdKUwbPORjU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00065

JSON explain

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