SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95ee78995108270302f7311aea25de5f6de77d136494a6b8e557ccd879730f14' 
  AND token = 'HYwul4+yuEgymhySuAiaP14fwYuRScuoHJDjlRo2Zb8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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