SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a10f6cdfe090b1cf1bb4226647ba652360654f3edbf70f8f06d561e5eb24a879' 
  AND token = 'b4jDpdeJdlsRTmdq/uCYm641oxPZvj77nHhGjVpOYLw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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