SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5696d9c0a699c02fc93ba897ab0af0ef21f46c6fbdb191b6766d243e4e04b870' 
  AND token = 'L2BL8W1NkWck7sxAEo8g07ji5mwW/TrGWdPgJKJekvg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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