SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4766adf9a2687dc4f8291a529d1d9cebd20df09da9016f285576f3d46b5efa4a' 
  AND token = 'vUWJ9BkhTXlQsuGhN4/wL+qgZbYtwDQjdK19RH0mJ/s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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