SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d600948d4fd2edffc1eda3014616e7056d0ee6c6495710de20bb9889c34b85b' 
  AND token = 'bv1xLEgwTTf04YMQxNhA0wwihquVP8haeW0iXT7aNgA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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