SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a171cf15bed61bc7ed3e29db984c4c75995977cb81f560c5c27f67079b1b68d' 
  AND token = 'QLj1bDsGgX3qqUi4PKJt6nwB77iGvMZCwgplVVOpbTM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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