SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c24cf5b47db71b93e6e42b197ddb680bc528a876844b42be19655a78efb5db4' 
  AND token = '2lUhOJz/uO42Ic4v4PQZ7R0iDsfATWEfNJWQPnkpVDw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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