SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd3f63e67275a8e96943c57f1650111735561328d0e9dca98df3ea5ad06cb831' 
  AND token = 'QoQ4K4QHR05gwNBEgSwfpQ92UHYL3HdY1UfWEC8rqfk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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