SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '89a68f080ac406099aa3081cae03ae6520bcd59e9e69e069e6bdc5699f729ce7' 
  AND token = 'HDkkqehSQlJvhwrJGQEUko6BwdY0Bwc4lIGeKJFGboA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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