SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0c9b66100a245abdab3aceb468c258d7cfe1b754bc7561f572561710e233973' 
  AND token = 'COT3PgVKwrNKta8iQ3tDHiZkHaUvH9yUz7XWq0RbcM8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

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