SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '3f08ca40f175286b6ee159baa00395e9e180938b00b45c4f43575ae13ae25851' 
  AND token = 'QjZYGBpbKXxo2djBAAKn/FraRlEa3fZNT+VkSNY+/Xg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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