SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0dd6c34645fb09fdf3e47b72b94ab614d0c1922ea244d190639a4813621c4705' 
  AND token = 'tbrYVO0yhVXJ9FUP8DCoy+Y/fzO7217DwIaC5JAPoiQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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