SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da850b65d8266423caa8a36c2180abee8d5a870ba01c5b886201981d541eaba6' 
  AND token = 'bTwNcFAx4cy8GI+zHy7abwppLWJDN0zeSdB8pOwOzNk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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