SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a90de9f5f26155377c6f303ef6896431d1ff5ee13c49b9a95ecfce33a12a9ff' 
  AND token = 'ABg8MmJuUl9fHxJy8altzEqyDiYKuaad5MYnWl4gY6I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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