SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c80acae660617b671eb3fcf1842fd8d5a1ed744b3c28f9b8ceca50079b4451c8' 
  AND token = 'eiKRozYsZnLu03w87N/bRav+umhAarr0OH9XHMseQXw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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