SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '925d488504595e01ae2dbc47534b192d281d4e82f47c0d2af7579dce8272802f' 
  AND token = 'Xg9KcsX5zEXDwNz7Udv2FDvtTSwi50sRLx9Y/6oLrAo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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