SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fdceb3529ce8b67089d6f60f63959a2a551bb305551852175b19daee0ca26bbf' 
  AND token = 'NIh18djLGy7B2RIBLGifDkYh/IaHuAzqS0W8GFRrR6k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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