SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f89ff677a452325f496a4d6a27cc96a962d9baa9875b4fbf83e55067f033cb14' 
  AND token = 'MQ2vFNXqpUPEnXnZQ/3RS42SyZYQzyyMO5bQZEpufFY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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