SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '964efa324d66e99a382b69f005ac8577e3802acb7660b16c952cd9a2d8bfc459' 
  AND token = 'Dwq+xBZAAK+XpbgssEdYwBqPgMf0ZkjDM9QVot/LPhc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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