SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb13648ed72ed0b13eb5e82902b02790efa7bf4c2a927152abce53e04b793143' 
  AND token = 'taZMeByUJOBd8R7XQLYadZGWuwVk4qThJ0+wbeiGDtE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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