SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca42a3954d8cb6cc12b614f36b864b659892f9ddd8807630a67fd3c79af4fca9' 
  AND token = '3WjRjR0XTKfDPwjVxjGU/Ehf8kiPNa2YoxZrPAK4HFY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}