SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '58bb570150d16742abf576c733ac19cad6db57a8d069e97f125831569f6c88d5' 
  AND token = 'BQx5zQ1ZQVJyXUFOcWMzvE4xNV5iKL7MMJx9l+YcdW8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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