SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '214d34a0ef2090644f4ae766043527dd139c9dea13163284ce6fd02c3b969728' 
  AND token = 'ZE9wmIuro4qSaWJ2rW3ZvMBqky+aorBXOCLSRSJSUFQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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