SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41f12f303f5087d413dae528b48d7e3f876869d7a73cf9d7ef61936f3ca3cb44' 
  AND token = 'diZu8nk9dsmWG2Z+vpTJuHxxaq/Q5SVBhDfSh9o6qyI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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