SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6efda842d39936bdc5face7b25ab22adc10d97248c2c86e476fd5645465600e3' 
  AND token = 'r9W0ZLfksGsH/vGHtn9sYuXXOtjFaPwbuDQNxujr7WU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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