SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '72e1d3569cd9342a036564bb0c63253fc76311fd474382a7816a34e402b335ca' 
  AND token = '+kpDw1RnNcZSCO1qaGM7a7TxbMvZ7jiAXvWCHXYsYhg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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