SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '60f0f7b416ee961b9628ac87e47f96b11ff58f3b1ae89369ccc37c449a592c66' 
  AND token = 'PnXJ/RMjt3+oazEV1IYgSnCzjI+fgGWucY+NtuRhVVc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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