SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8329c67fc0cc0ba37c7017636885f7e480c7a42ba394fc0a06387aaf9adbac62' 
  AND token = 'H+NoWDwPl7p8MGSoNcVqtexYNwmojy30RZPQhggWBow=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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