SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d3e20cd39c55bfdb85d001036edeca0e783c8dd93119d0ae2fdd492b7caffbc' 
  AND token = '3X6PhzSKFhlKHZvfXQrUVsHBd0Q4otDQukMqUBVoSow=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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