SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '609f860eb31aa6457249ed57ecf83ff8eb703352bc99f9bce6249815f99bcb33' 
  AND token = 'LqbxLzMdvjFGWAsbTrShUibnFZAgEh0onWab22eoeYU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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