SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '277cca121cfb446b6b998fbfb8dd35033e99633b9248c463718cb763aba46bf3' 
  AND token = 'puM/zYBVg9hEUjWuHvaF2TIjX/BjGRzKf7yyl99uQmo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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