SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9586f18af8b29e20b0e7472c26da165d7465dc66143e6aab6cb813f1c589756' 
  AND token = '0vgl+ceuzOHyojvq+5es+KWFmJy4wfL+2RagQ27619w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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