SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '361d8269e36fa84710cb9505e88f00b9273d42e6a998b8be7630f52939cc8e87' 
  AND token = '9HcvKs8d0ecqoDwv791ypHDZybM9ArQwS3MPcdnGzVk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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