SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e6021a4338bd62f8e782e5d66217a3010dca1e01d7a798a924997ac59afe6ff9' 
  AND token = 'QlsOcvtLyoPaJ/fJY75PtfVatbkPltkpteMztDlMiMw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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