SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f107106c439eb8032abef4b7bfef1c3af05940d6bbfcbf1debd0b4f350be61b8' 
  AND token = 'HfNBYggWXZ/xVV3zy+bWVZfSy6GwRVVS9S+4oeVTSkA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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