SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb98bceee4542c4f3c311be73ab24281a9feaa73deafa17efd80adf97969d7ff' 
  AND token = 'Bgqmf9YALILAYjVnoX6lJX0arhXskFsYHuBiMn80qdw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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