SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '779228e88448fae74ec6b5aa0131da4c4f118d7ea968b6b114febf81f4ec75db' 
  AND token = '8BqrKHCUkMQB4yUT5yOtowPtcmBMlDzVkNGWU16HcSI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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