SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6190786ec03393722070292fa47b3181f27d40e662b7f83c457e81ac71093788' 
  AND token = 'aUjIDy4EMjTlQSaKIeWe7Zue9Vvtpm2Spko4xTYScY0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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