SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e744c615e56d7898e941973f361cb35169365ae68408245e9b760c12fbe5bac5' 
  AND token = '3zdYlQdjpeBmhoUomvUSQosqJdalw32xZNl9DwsE2jE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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