SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f366b5736ed96a03ec27a342959579f83f07ed6911c4198d182e9161b403260' 
  AND token = 'IdrtGTAwGjrxDJLtnJngR87tvvB9w32igK+7ugLXtDg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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