SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'db9781b24e028dd848b56f097791861853742347ada0412d869f1abbf8ab55dd' 
  AND token = 'SpCwOcDpHrzzN9aeXbgQR9LZXWGHO9ajNHzlftJbe9s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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