SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e36cc46bd7aadc93221addbe0136db8540791d87a4281cdf0df19d42534c940e' 
  AND token = 'QTXShfyAg/843Ut14RWn0SnOdo/xPe+/mDUc/QwTRjo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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