SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84dfeb7656a85f95625e9e482072b4e5a4ed585b49501486c34736ca922d2238' 
  AND token = 'Ijbn+fhRJ0iCR0JUahUGpXpBGO1dYDg04PpelgnZZzI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}