SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'ea6af91daa088a36074f6ac69ef48ddbd69a584ac106d96f7d024a91ce9311ae' 
  AND token = 'clWyhDBJMWxoSVN1jdz7AHMkT0LJd1bXrVthNDOOPzQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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