SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7afe652eb8acd6849043075eb1db99a17d0af68f764b6a8c42b6677cb9ebd091' 
  AND token = 'Vjn+OlUABy3BhYV1G/ElLYYfDZh3C1dfdvPVnB4oGSw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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