SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad45c840df9815f4fedfcd690ea7ad77fd0c73d9a5bb85e8015665331028212c' 
  AND token = 'ToMtZPY5LpBftSGt9zUQegJw+sFg04IvaHzVifjL61g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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