SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d35e8d8ba29151ffacab98669815333cd3ab2877684bc181d38693a36b01d6b' 
  AND token = 'ATIQ4oqUgXt6YlEK3xR9ZcOf5n2gVSy7wDOkuWCp2J0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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