SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b1195d0804709e20986a09c550cf3ae723acd28b5025856d6c92782d6e12eae' 
  AND token = 'b/Qmy1rqNvXj/UJhWms2K0HofdPffYypUEiD1bS96zs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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