SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '60f291feca90edd1c0f79dcca6cdd28c442a5b74c9193576b655e185b69ef24b' 
  AND token = 'S0DBALHCyg7nYy0XvqUQTub2CW2sBqIQGhCmrQr6aP8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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